German plates are indeed white front and rear and made from different material to the standard UK plates. They use a different font and typeface also. There are a few places that do them online (dubmeister and germanplates) and they are around £20 I believe.
As for legality, they are not road legal and you could get a ticket everytime you take the car out with them on technically (get repeated tickets and you will end up being reported to court rather than even getting a ticket too). I know lots of people have german plates but most would at least use a yellow rear plate.....using a white one on the rear will attract plenty attention from the police.
In the coming months the law is going to get a lot tougher on number plates, especially font and typefaces used...basically the new digital numberplate recognition systems can't read non-standard plates well and this will result in lost cash from speed cameras, road tax cameras and congestion and toll cameras. Expect plenty of pulls from the traffic police....
In conclusion, if you can get some made then cool.....but it could become costly in terms of tickets and a whole lot of hassle....use them for shows off the road but stick with the regular yellow plates otherwise would be my own advice. Hope that helps mate.
